The RAD52 gene in Saccharomyces cerevisiae controls the repair of ionizing radiation-induced DNA double-strand breaks, radiation-induced recombination, and recombination in meiotic cells. The rad52 mutant of Saccharoymces cerevisiae was shown to be deficient in an alkaline deoxyribonuclease by the use of immuno-precipitation techniques in conjunction with a nuclease assay. Further analysis of this alkaline deoxyribonuclease in RAD52 during meiosis reveals that its level reaches maximum activity at a time corresponding to the beginning of DNA synthesis and recombination, whereas in a rad52 mutant, the level is low and remains constant throughout. This alkaline deoxyribonuclease has been purified to homogenicity and has been found to be an endo-exonuclease that requires Mg2+ for activity and has a molecular weight of about 70 K as determined by SDS-polycrylamide gel electrophoresis.